VAT Orange 2

When the original dyes in strong reducing agent and under the action of alkali, so that reduction of a soluble dye leuco salt, its fiber affinity to dye fibers. Reduction of dye powder dissolved with the insurance - caustic soda method, in the insurance powder, caustic soda dissolved into leuco reduction after salt, that is a direct nature cellulose fiber, first adsorbed on the fiber surface, and then spread within the fiber complete fiber dyeing, as a direct dye on the fiber is greater, so the faster the rate of dyeing fibers, dye transfer dyeing properties are poor, is difficult to dye evenly, so dye can add a small amount of slow process agent: If Peregal O, etc.. The use of sodium hydrosulfite - caustic soda dissolved reduction method should be master of caustic soda, sodium hydrosulfite, and the amount of reduction temperature, can dye properly otherwise the dye will produce excessive reduction or hydrolysis and rearrangement reactions, which are not normal, causing dye damage wilt dark color, color fastness decreased. Dye to the fibers on the leuco dye to undergo oxidation, making it back into the fiber in the reduction of the original insoluble dye. Reducing the oxidation of leuco dyes can be cold water leaching (ie oxygen in the water oxidation), take the air (air oxidation) or dipping liquid oxide oxidation method used depends on the oxidation of leuco dye oxidation rate. Commonly used oxidants are sodium perborate, hydrogen peroxide and so on. Some of the oxidative dye under the conditions of severe over-oxidation occurs, the color change.